diff --git a/fuzz/Cargo.toml b/fuzz/Cargo.toml
index 55d8543..1fd6d3e 100644
--- a/fuzz/Cargo.toml
+++ b/fuzz/Cargo.toml
@@ -10,7 +10,7 @@ edition = "2018"
 cargo-fuzz = true
 
 [dependencies]
-libfuzzer-sys = "0.3"
+libfuzzer-sys = "0.4"
 wasm-smith = "0.8"
 
 [dependencies.waffle]
diff --git a/fuzz/fuzz_targets/parse_ir.rs b/fuzz/fuzz_targets/parse_ir.rs
index d662856..24e3021 100644
--- a/fuzz/fuzz_targets/parse_ir.rs
+++ b/fuzz/fuzz_targets/parse_ir.rs
@@ -5,5 +5,5 @@ use waffle::frontend::wasm_to_ir;
 use wasm_smith::Module;
 
 fuzz_target!(|module: Module| {
-    let _parsed_module = wasm_to_ir(module.to_bytes()).unwrap();
+    let _parsed_module = wasm_to_ir(&module.to_bytes()[..]).unwrap();
 });